The present disclosure relates to an image forming apparatus that can transmit image data via a public switched telephone network.
In general, there is known an image forming apparatus that can execute a facsimile communication process in which image data is transmitted or received via a public switched telephone network. It is noted that in this type of image forming apparatus, it is possible to determine whether or not the public switched telephone network is normally connected by detecting a line voltage that is applied from the public switched telephone network.